What Is a Sling?

A sling is a flexible lifting device specifically designed for hoisting and moving loads. It is widely used in construction, manufacturing, logistics, ports, and the petrochemical industry. Compared to traditional wire ropes or chains, lifting slings offer many advantages such as being lightweight, non-damaging to loads, flexible in use, and highly safe—making them an indispensable tool in modern lifting operations.

Definition of a Sling

A sling is made from high-strength synthetic fibers such as polyester, nylon, or polypropylene. It comes in either flat or round form and is reinforced by sewing techniques to enhance strength. The sling may include protective sleeves, reinforced loops, or metal fittings to suit different working conditions. Based on structure, slings are classified into flat webbing slings and round slings, and they are selected according to load weight, shape, and environment.

Types of Slings

• Flat Webbing Sling: Made of multiple layers of high-strength polyester fibers, it has a wide and flat surface ideal for lifting flat and regular-shaped objects. The eyes are typically reinforced for better wear resistance and safety.

• Round Sling: Made of continuous loops of high-strength fiber yarns encased in a protective sleeve. It offers excellent flexibility, load distribution, and reduced risk of twisting. Ideal for lifting irregular or delicate items, it provides better protection than flat slings.

Common Applications of Slings

• Machinery Lifting: Used to hoist machines, tools, or steel components in manufacturing, assembly, and installation sites.

• Ports and Logistics: Widely used in container handling and bulk material movement due to its flexibility and non-damaging nature.

• Construction: Employed to lift rebar, formwork, precast panels, etc., on construction sites, often in combination with cranes.

• Wind Power and Heavy Industry: Used to hoist large structural parts like wind turbine blades or towers, often utilizing round slings for their protection and strength.

• Aerospace and Precision Equipment Handling: Ideal for lifting valuable or sensitive equipment, as slings prevent scratches and deformation.

Advantages of Lifting Slings

• Soft and Non-damaging: Compared to steel wire ropes, slings do not scratch or compress load surfaces, making them suitable for coated or precision items.

• Lightweight and Easy to Handle: Much lighter than steel ropes of equivalent strength, slings are easy to transport, set up, and store—greatly improving efficiency.

• High Strength and Safety Factor: 

  The design of lifting slings generally adopts safety factors of 5:1, 7:1, or 8:1 to ensure safe usage.

• Abrasion and Corrosion Resistant: Materials offer excellent resistance to water, oil, and chemicals, allowing use in complex environments.

• Customizable: Available in various lengths, widths, layers, and end fittings to meet diverse lifting needs.

How to Select the Right Sling

When choosing a lifting sling, consider the following factors:

• Load Weight and Type: Choose the appropriate type (flat or round), rated capacity, and length based on the shape, weight, and surface of the load.

• Lifting Method: Different lifting configurations—straight lift, U-lift, or double-leg—require different sling widths and structures.

• Frequency and Environment: For frequent use or harsh environments (e.g., high temperature, acid/alkali, humidity), select slings with protective coatings or special materials.

• Standards and Certifications: Choose products that comply with relevant standards such as EN 1492-1/2, ASME B30.9, or ISO 4878 to ensure quality and safety.